STREAM WATER-GROUNDWATER INTERACTION CHANGES IN LOWER NAKDONG RIVER BASIN BY USING THE TIME SERIES ANALYSIS AND GROUNDWATER QUALITY |
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학술지명 국제관개배수학회
저자 김규범,오윤영,함세영,이충무
발표일 2014-09-15
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Total of sixteen river dams has been constructed in four major rivers in South Korea (eight dams at the Nakdong River, three dams at the Han River and Geum River, respectively, and two dams at the Yeongsan River) for the purpose of flood control and effective water resource use regarding climate change. However, the river dam construction induced groundwater level rising and stream water-groundwater interaction changing at the upstream regions of the river dams. In this study, we examined stream water-groundwater interaction properties by using the time series analysis of groundwater level and river water level with groundwater quality at the Changreong-Haman river dam in lower Nakdong River. Total of 34 manually monitoring wells and 5 automatic monitoring wells in the riparian zone of the Gwangryeo Stream and Iryeong Stream tributaries of the Nakdong River were observed during Mayl 2011?September 2013 with river level(Ducknam observatory station) and rainfall(Jindong rainfall station). As a result of this study, the groundwater level raised up with an average of 1.62 m for the observed period. The cross-correlation function of groundwater level and Nakdong river level has changed 0.04-0.68(before river dam) to 0.05-0.71(after river dam) and response time ranged 3-229 hours(before river dam) to 1-251 hours(after river dam). Also, groundwater quality displayed a lower Ca2+, HCO3-, and CO32- concentration and higher NO3- concentration near the Nakdong River after river dam construction. These are indicating a greater interaction between groundwater and river water due to the river dam. |